One of the largest losses incurred by a production facility is the cost of downtime. Downtime is the time during which a production line is shut down due to failure of one of its parts. In the case of spot welding, a welding gun failure can result from a breakdown of the gun actuator. Failure of a welding gun can shut down an entire production line. The gun is unusable until the actuator can be replaced. Typically it takes about ten minutes to remove a failed actuator and replace it with a working one.